We just deployed ESXi v5 at our facility, and will be moving our production servers to our VM environment this week. Prior to moving production servers, I am trying to convert a XP Pro desktop to a VM. The desktop will need to have a 75GB hard drive, so I set the C drive on the vm up to be 100GB.

I started a P2V on 3/3/2012 at 3:52 pm cst, and as of today, the converter is showing that it still needs 22 hours to complete. Prior to this test, we ran a P2V on a Win7 Pro laptop, and it took about 52 min for 25 GB.

I looked at perf mon in vCenter for each of our two hosts, and nothing is standing out at me indicating that there is a problem. We have a SAN on the back end, and it does not appear to have latency issues either.

The XP Pro desktop is only using 2% of the CPU, and there is plenty of RAM available as well. Network utilization on the desktop is a .5% on a 1Gbps NIC.

Virus scan software has been removed from the desktop for the P2V, and I ran a defrag prior as well.

So, what are the best practices in determining why this is taking so long to convert?

Seems you DO have a latency on somewhere. Check the following: install vSphere client on this XP, and try to upload some huge file using browse datastore (it uses NFC, same mechanism as Converter). Check if the XP is not having disk read latency.